Grinding wheel construction



April 3, 1934, E. J. LINTEREUR GRINDING WHEELCONSTRUGTION f0 JJ 1/ feral/r mm V g Flled Sept 21 1931 I Jkforrzey Patented Apr. 3, 1934 UNITED STATES PATENT OFFICE 1 Claim.

This invention relates to grinding wheel constructions of the type utilizing a ring of resilient material which is adapted to grip an encircling band of abrasive material when expanded radially outward.

An object of the invention is to provide an inexpensive construction of this character, having but few parts of simple arrangement which will rotate truly without any appreciable side sway or wobbling.

Another object of the invention is to provide a construction in which the centrifugal expansion. of the resilient ring is utilized to grip the encircling band of abrasive material, .and by which this expansion is made uniform.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a longitudinal, central section of a wheel constructed in accordance with the invention, the parts being separated for the sake of clearness;

Figure 2 is a similar view with the parts in their normal operative position;

Figure 3 is a section along line 3-3 of Figure 2; and

Figure 4 is a longitudinal central section of a modified form of the construction.

In carrying out my invention I utilize a rotatable shaft 1 having a reduced end portion 2 upon which the various parts are to be mounted. A suitable ring of resilient material 3, such as rubber is provided, having a normal outside diameter slightly less than the diameter of an encircling band of abrasive material 4 which the ring 3 is adapted to grip. The ring 3 is mounted on the reduced end portion 2 of the shaft between two washers 5. The outer face of one washerabuts a shoulder 6 formed by the reduction in the diameter of the shaft 1 while the outer face of the other washer abuts a nut '7 which is threaded to the reduced end portion 2 of the shaft. By screwing the nut inwardly the ring 3 is compressed or squeezed between the washers 5 and thus expanded radially outward so as to grip 45 the encircling band of abrasive material 4. Since the ring 3 will expand substantially when rotated, it is only necessary at the outset to screw the nut 7 inwardly until the ring barely grips the encircling band, this ordinarily being sufficient to prevent the band from slipping off when rotation is begun. The pressure required to effect this initial expansion will depend, among other things, upon the radial thickness of the ring. In prior constructions of this character the radial thickness of the ring has extended from the shaft to core.

the periphery of the ring which necessitated a pressure so great that it ordinarily required the use of wrenches or similar tools. According to my invention, the radial extent of the bearing or side surfaces of the ring is reduced so as to effect a reduction in the initial squeezing pressure. This preferably is accomplished by increasing the internal diameter of the ring, and is carried out to an extent such as to leave the bearing surface sufficient only to provide an effective grip for the washers. The effectiveness of the washers 5 in expanding the ring, can be further increased by slanting the bearing surfaces of the ring, so that they converge inwardly and shaping the washer to conform.

The extent to which the radial bearing surface of the ring may be reduced can of course be varied considerably. I have found that good results can be obtained with a ring proportioned as shown in Figures 1 to 3 inclusive. In this particular case with an external diameter of 2%" the pressure required for the initial expansion is so light that it permits the nut 7 to be manipulated by hand, either to effect the engagement or release of the band 4.

With the ring spaced from the shaft as shown it is necessary to provide some means for centering it so as to insure true rotation. This may be accomplished in any suitable manner as by providing the ring with a suitable tightly fitted I prefer, however, to utilize as a core a washer 8 which extends inwardly of the ring to a substantial degree. This washer functions not only as a core to support and center the ring, but, in addition, by having the ring molded to it. the washer is made to function as a reinforcing member which tends to prevent the ring from expanding more at the center than it does at the sides and thus tends to make the expansion of the ring more uniform than it otherwise would be.

The ring will ordinarily be held against rotation or angular movement relative to the shaft by the gripping effect obtained through the combined action of the washers 5, shoulder 6 and nut '7. If desired, however, this result may be insured by providing the shaft 2 with a key 9 for engaging the washer 8.

In Figure 4 a modified form of construction is shown wherein a cylindrical core 8a is utilized in place of the washer 8. The cylindrical core 8a is dimensioned to fit closely within the central opening of the ring 2, but preferably is made of a width slightly smaller than the ring 3 so as to enable the ring to be compressed by the washer 5. In this constructiomas in other one, it is I as an abrasive band, said ring having side bearing surfaces, a washer extending radially into the interior of said ring and secured thereto and means for engaging the side bearing surfaces to compress the ring and cause its radial expansion.

EDMUND J. LINTEREUR. 

